Comparison of carbon nanotubes and nanodisks as percolative fillers in electrically conductive composites

Composites based on polyvinylalcohol have been fabricated from solution with either carbon nanotubes or carbon nanodisks as fillers. Addition of both filler types resulted in conductivity scaling with volume fraction according to sigma = sigma(0)(p - p(c))(t). The nanotube-based composites displayed percolation thresholds of 0.4 vol.% compared to 2.1 vol.% for the nanodisks, which is higher than expected due to disk alignment. Maximum conductivities observed were similar to 1 S m(-1) for both composite types. Values of sigma(0) of 20 and 40 S m(-1) were calculated for nanotubes and nanodisks, respectively. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.